Why Does the Car Paint Feel Gritty After Spraying?
3 Answers
Spray paint that is not smooth and feels gritty is due to the base layer not being sanded flat, the sprayed paint layer being too thin, or poor working conditions where dust falls during spraying, or the paint viscosity being inappropriate, leading to poor spraying results. For grit after spraying, allow the paint film to fully cure. For minor dirty particles, sandpaper can be used to sand them down, followed by polishing. If the impurity particles are deeply embedded or the paint film shows synthetic resin paint, the paint film needs to be sanded smooth and repainted. Methods to prevent gritty spray paint include ensuring clothes are clean and dust-free before spraying, blowing off dust from the edges of decorative parts or sheet metal seams; before spraying each layer of paint, clean the surface with a cleaner and dust-free cloth; keep the spray booth clean and dust-free. Sanding operations are prohibited in the spray booth. If necessary, moisten the periphery and floor of the spray booth to ensure the proper functioning of the air filtration system; also, keep all materials clean, and seal material containers before use.
Finding a grainy texture after car painting is quite common. As someone who frequently works on cars, I believe the root cause mostly lies in poor control of the painting process details. If the paint booth is dusty or the ventilation system isn't functioning well, tiny dust particles can float onto the wet paint and stick firmly, leaving a rough surface after drying. Inadequate cleaning of the spray gun leaving old paint residue can mix with the new paint, creating small bumps. Uneven paint mixing is another issue—insufficient stirring causes solvents and pigments to separate, leading to clumping during application. Temperature and humidity control is also crucial; too high a temperature makes the paint dry too quickly, preventing smooth leveling and resulting in graininess. To avoid this, thoroughly clean the environment and vehicle body before painting, use professional spray guns to ensure they're free of impurities, and inspect and polish the surface promptly after painting. From experience, a bit of careful attention can solve the problem.
Speaking of paint texture issues, this problem is particularly common in DIY spray painting. I suspect it's mostly due to a dirty painting environment. For example, leaving the garage door open allows dust to settle on the wet paint surface. Improper spray gun operation with unstable pressure can cause uneven paint distribution, forming small lumps. Incorrect paint mixing ratios may also create small bumps. Applying paint directly over un-sanded primer can reveal underlying impurities. Sudden temperature changes during drying can cause the paint to shrink and form particles. The remedy is to lightly sand with fine sandpaper and apply a clear coat to mask the imperfections. For prevention, the key is to choose an enclosed space for painting, thoroughly clean the surface, and vacuum dust before starting. In daily car maintenance, these small issues can accumulate into major problems if neglected.
